87bob

Who has done a 700R4 rebuild? How did it turn out? Would you do it again? I understand there are alot of steps and a few specialized tools needed. I understand if you do it methodicly it can be easly done. I would like to do all the up grades that are possible and know that my horsepower will never get close to the potential failure range.Oppinions please!

Phobos84

I never built a 700r4. I did do a TransGo shift kit in one but that was as close as I got. I have however built a 4L80e and that transmission is still in my 84 right now. There are a lot of very good videos that walk you through it. I know there are people who would disagree with me but I really learned a lot from the Precision Transmission YouTube channel. Most of his videos aren't him building a transmission. Most of them are him taking them apart and showing why they failed. He shows what to look out for in worn parts. Of course a service manual would help here but they are kind of lacking in this department. Seeing someone do this is really what helped me.

87bob

How did you marry the center support to the back end of the trans.

C409

About 15 years ago I built 2 700's and 1 4L60E ... I highly recommend the ATSG manual and also the Haynes GM transmission repair manual . Have a large work area to systematically lay out the parts as you remove them from your trans (they go back in in reverse order) . I made an adapter out of 4"x4" angle to attach the trans to an engine stand using several pan rail bolts on the pass side of the trans . The manuals won't go into depth on any performance upgrades available so you should seek some guidance there . As a minimum , I recommend the "beast" shell , quality clutches & steels (Borg Warner or Alto reds) if you use the wide band you have to have a nearly new surface on the input drum (I always used new GM) . If you're starting out with a vette trans , the OG servo is good , otherwise a Superior or equivalent 2nd & 4th servo works well . A Transgo 700-2-3 shift kit is a good choice . I also replaced all the bushings in the trans ... tight slipper bearing clearances help maintain internal pressure .
Make friends with a transmission parts supplier near you ... depending on your State's requirements , get a tax ID # AKA re-sale certificate . This opens the door for establishing an account at any parts house and getting wholesale pricing on parts . Sonnax has a LOT of performance upgrade parts for the 700R4 but they can be pricey . If you can , you should start with an '87 or newer (they have an auxiliary valve body) trans . Outwardly identified by a cam lobe shaped casting line on the passenger side of the case that encircles the trans cooler fittings .
I still have one of my 700R4's with slipping 3-4 clutches but lots of goodies inside ... and the 4L60E ... bad-*** trans has a Rossler Trans Brake . I'm currently racing with a Powerglide in my '87 .

Phobos84

Well it was a pain in the ***. When you're ready to put it together it works best to have it lifted vertically so gravity helps you. That works for a while but being I was using a cherry picker style engine hoist to do that the chains kept getting in the way. I walked out of the garage several times frustrated and just needed to take a break from it. I probably had it apart and back together 20 times before I got the tolerance right. But it was worth it. I hammer that transmission and it takes everything I throw at it.

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drive it

parts kits or completely rebuilt all levels of hp. https://probuiltautomatics.com/

mike1111

I rebuild a 700r4. used books and 4L60E videos (transmissionbench.com). couldn't of done it without step by step video. need a few tool. upgraded everything I could ,but its not really needed. mine works great.

87bob

Great info, thanks!

87bob

Thank you for the info.

Hit Man X

It is a really simple trans, I build 4L60Es for my truck and SUVs. Buy an ATSG manual first off and flip through it, see if you like complex assemblies. I do enough autos where I bought a foot press from a tool supplier in San Antonio, there are just a few tools needed for the trans but you can probably DIY something if handy. This guy has slick vids - http://transmissionbench.com/4L60Evideos.html

Valve body is always the most critical area to me. For me I tend to spend 5-8hrs on one as I fully disassemble it and lay the springs and valves out on a broiler sheet (has valleys and peaks). I clean all bores with a bore polishing tool from Superior Transmission, all valves, all springs, then reassemble with a shift kit of some sort. I always have the SKs setup as mild as one can go, then increase firmness as needed. It is far harder to decrease firmness than to increase. I prefer a quick, crisp shift not a harsh one. Think how old Mercedes transmissions drove from the '80s and back if you guys have ever driven one.

I buy parts from Transtar, they have warehouses all over the US. Start with at least a full paper and rubber kit, Precision is who I mostly use there. All other stuff I typically line item order. Sonnax has a real slick HD 3-4 backing plate kit that allows +1 clutch in the 3-4 (direct) drum for seven with full thickness bits (same as 4L65E). I have heard good stuff about the Raybestos Z-pack, no experience. That is the main failure point in these as the OE tend to 'cone' if you will. Use the wide 2-4 band and a new reverse input drum. I like Alto high energy graphite clutches. Make sure all bushings are new. Consider five pinion planets if the power level warrants it, you can fully rollerize the rear, the HD sun shell known as The Beast or Sonnax's. Vette trans should already have the larger 'Vette' servo which I think usually are 093 models. I like the billet OD servo from Superior.

There are adapters that go into engine stands to support the case or you can build one out of some scrap 2x4s and plywood. I did for my 4HP24s I do and 722.3s.

Also, always try to seek out the latest model made of your trans if possible for a core. Internal lube and hard parts are always updated over the years.